Grade indicator



Sept. 13, 1949. LANGLEY GRADE INDICATOR Filed Feb. 21, 1947 Y. R Y 5 5 mm MW W W 5 m l/. m I m M. L vx W .1 5 v fin W W Z w H H m V Patented Sept. 13, n 1949 I STATES PATENT OFFICE TINDIUATGR Glenn Langley, Davenpol' flwash. Application February 21, 194 7, =Se'1'ial No."730,089

l' Glaim. 1

The present invention relates to the general class (if measuring and testing appliancesof the liquid level or depth gagetype employing liquid displacement or replenishment in combination with a transparent -s'i'glit tube, and'more specificall'y *to an improved grade indicator or liquid level instrument, which while adapted for various purposes, is especially adapted for use on vehicles.

-As an 'example of the utility of the instrument of my invention the grade indicator is mounted upon a tractor or road-grading implement of the wheel type'or'of the endless track type employed in grading roads or highways at a predetermined gradient. =By observing the position of theindicator the driver of the road grading machine is enabled 'to maintain the predetermined declines, or-inclineaand slopes of the road-"surface as the road or highway is being built.

The instrument of my invention is alsoadapted for use on threshnig machines and other agricultural implements'where itisnecessary to maintain a '.predetermined level or'igrade of the machine or implement to ipreve'nt undue tipping or tilting.

The primary object of the invention is the provision of an instrument comprising a minimum number of component parts that may with facility be manufactured at low cost of production, and assembled wtih convenience to provide a grade indicator that may readily be installed upon the vehicle and accurately adjusted to initial position by means of a level of the carpenters type, as part of the equipment of the vehicle.

The invention consists in certain novel features of construction and combinations and arrangements of parts as will hereinafter be described and more specifically set forth in the appended claim.

In the accompanying drawings I have illustrated one complete example of a physical embodiment of my invention adapted for use on a road-grading tractor in which the parts are combined and arranged in accord with one mode I have devised for the practical application of the principles of my invention. It will however, be understood that various changes and alterations are contemplated and may be made in these exemplifying drawings and mechanical structures, within the scope of my claim, without departing from the principles of my invention.

Figure 1 is a view in side elevation, partly broken away for convenience of illustration, of a grade indicator in which my invention is embodied, and adapted for installation on a vehicle.

:Figure -.2 :isz'a vertical sectional view of the indicating instrument.

*Figure 3'is-ian enlarged detail vertical sectional view showing the low'er -end of the sight glaSstube', the housing and the agageirod mounted in the base of z the iihdiCfitOIZ Figure 4 is an enlarged transverse -:sectional view atr'line ile lof :Fig. 2.

Figure 5 is an enlargedzdetail verticalzsectional view of :theliquidreser'voir.

Figure 6 is a transverse detail sectional view at line Ei--6 of Fig.2 through the "top cap and the glass tube.

A-s indicated in the assembly view Fig. '1 the parts of the instrument :are Imountedupon. a' baseboard I that is installed inxpreciselyadjusted position and leveled .011 :a supporting part .;or frameof the vehicle, and' -a; preferablycylindrical liquid reservoir -2, containing arsuitable colored liquid is partly filled I approximately to the 1 liquid level L in Fig. 1. Thezfixedreservoiris provided with :a double wall ventilating=closureor cap that is X equipped with breather'ports or ventilating ports 4, and constructed to prevent leaks of the liquid that might otherwise be caused by splashing due to irregular movements of the vehicle.

At the base of the reservoir a feed pipe or supply pipe 5 is connected as at 6, and provided with a regulating valve 1 to adjust the flow of the colored liquid from and to the reservoir, and to and from the upright indicator or instrument that is spaced from the reservoir and mounted on the base board in position where it may readily be observed by the driver, or other attendant, of the vehicle with which the instrument is employed.

The measuring gage or indicator is mounted upon a substantial base or block 8 that is rigidly fastened to the base board, and it is provided with a laterally extending, curved duct 9 opening at the exterior of the base and to which the feed pipe 5 is connected. At the center of the base the duct 9 opens into the bottom of a transparent sight tube ll], of glass or other suitable material, and the open bottom of the tube is packed and sealed in the base by use of a flanged screw ring I I, so that a column of the colored liquid will seek its level in the indicator tube.

At its upper end the sight tube is closed by means of packed cap l2, and vent ports l3 are provided to compensate for the desired smooth and regular flow of the liquid between the vented reservoir and the vented sight tube.

The sight tube is enclosed and protected by means of a generally cylindrical, slotted housing or guard I4 to which the top cap is secured by screws l5, and the lower internally threaded end of the guard is threaded or screwed in an annular recess of the base, at l6.

Within the housing and exterior of the sight tube is mounted an upright gage rod H in the nature of a threaded screw bar of resilient material, with its lower end journaled to turn in a bottom bearing ring I8 having a stud bolt l9 supported in the adjacent wall of the housing or guard, and the upper end of the gage rod is journaled in a bore of the cap l2 and provided with a hand knob or head l1 exterior of the cap.

An adjustable gage or indicator is mounted on the upright tube and gage bar, and as indicated the gage includes a number of vertically spaced slide rings 20 that encircle the sight tube and are slidable thereon, and a radially or laterally projecting lug 2| that is slotted to provide two friction faces in sliding contact with the housing l4.

As indicated in Fig. 2, the threaded gage rod of resilient material is laterally flexed to offset position of the threaded lug 2| through which the rod passes, with relation to the upper and lower end bearings for the rod. Due to this frictional engagement of the gage with the housing or guard, by turning the head [1' of the threaded gage bar, the indicator or gage may beraised or lowered in sliding engagement with the guard and the tube.

The central one of the three rings 20 of the gage is used as an indicator in connection with the level of the column of colored liquid in the sight tube, and in relation to a predetermined level mark on the rotary gage rod.

In a road building operation and grading its surface the predetermined gradient is first secured by turning the head ll' to raise or lower the gage and adjust the central ring 20 withrelation to the central level mark on the gage rod, and this position of the gage is thereafter maintained by frictional contact between the gage and the adjoining face of the guard or housing. The road surface is then graded with an incline, or with a decline until the level of the colored liquid in the sight tube registers with or corresponds to the central gage ring on the gage. The gage and the sight tube are in position for convenient observation by the driver of the grading implement, and he operates the implement as indicated by the gage and liquid level.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

In a grade indicator of the type described, the combination with a housing having a base and 'top cap, a centrally arranged sight tube mounted in the base and cap and means for supplying a column of liquid for the tube, of a resilient screw bar having end journals and forming a rotatable gage rod located between the housing and the tube, a gage having a gage-rin slidably adjustable on the tube, and said gage having an ofiset lug provided with a threaded bore parallel with the tube for the gage rod, whereby the rod is laterally flexed and the gage is retained in fric-' tional contact with the housing.

GLENN LANGLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain 1887 

